Irrational Violence

One of my professors once wrote, in the 1970s, that our societies could come to experience "unmotivated violence and blind terrorism". Recently I blogged that a cousin of wife E had been stopped and stabbed in a township, and his tyres slashed. According to the hospital, he could easily have been dead. There was no discernable motive. I asked one of my activist friends why. What is behind such behaviour? He said one cannot reduce it to reasons: "This thing has no formulae." OBSERVATION: At least, it is hard to discern a reason.